Allow clear all button in overview be clickable if visible

Test: enter overview, make sure clear all button is invisible, try to
tap its location
Fixes: 110432640

Change-Id: I7531e4c6cfdcc9a29d98da24a73c32b8080e013c

1 files changed, 8 insertions, 2 deletions

diff --git a/quickstep/src/com/android/quickstep/views/ClearAllButton.java b/quickstep/src/com/android/quickstep/views/ClearAllButton.java
index 3911931b1..fbecd8486 100644
--- a/quickstep/src/com/android/quickstep/views/ClearAllButton.java
+++ b/quickstep/src/com/android/quickstep/views/ClearAllButton.java
@@ -54,7 +54,7 @@ public class ClearAllButton extends Button implements PageCallbacks {
     public void setContentAlpha(float alpha) {
         if (mContentAlpha != alpha) {
             mContentAlpha = alpha;
-            setAlpha(mScrollAlpha * mContentAlpha);
+            updateAlpha();
         }
     }
 
@@ -68,6 +68,12 @@ public class ClearAllButton extends Button implements PageCallbacks {
         float shift = Math.min(scrollState.scrollFromEdge, width);
         setTranslationX(mIsRtl ? (mScrollOffset - shift) : (mScrollOffset + shift));
         mScrollAlpha = 1 - shift / width;
-        setAlpha(mScrollAlpha * mContentAlpha);
+        updateAlpha();
+    }
+
+    private void updateAlpha() {
+        final float alpha = mScrollAlpha * mContentAlpha;
+        setAlpha(alpha);
+        setClickable(alpha == 1);
     }
 }